Background information:
Enzymes are biological molecules (proteins) that act as catalysts and help complex reactions occur. The enzyme grabs on to the substrate at a special area called the active site. The combination is called the enzyme/substrate complex. Enzymes are very specific and don\'t just grab on to any molecule. The active site is a specially shaped area of the enzyme that fits around the substrate. The activity of enzymes is affected by three factors; temperature, concentration, and pH. Changes in any of these factors affect the activity of an enzyme.
Lipase is an enzyme the body uses to break down fats in food so they can be absorbed in the intestines. Lipase is produced in the pancreas, mouth, and stomach. Most people produce enough pancreatic lipase, but people with cystic fibrosis, Crohn disease, and celiac disease may not have enough lipase to get the nutrition they need from food. Uses of lipase: Most people do not need additional lipase. However, people with the following conditions may find lipase supplements helpful. Celiac disease, Indigestion, Cystic fibrosis Lipase supplements are usually derived from animal enzymes, although plant sources have become increasingly popular. Lipase may be taken in combination with protease and amylase enzymes. These pancreatic enzymes are available in tablet and capsule form.
Research question:
How different concentrations levels (1%, 2%, 3%, 4%, and 5 %,) of the enzyme lipase affect the enzymatic activity that will be allowed to act on the same amount of milk( Triglycerides are the major type of lipid in milk fat. Triglycerides are composed of three fatty acids covalently bound to a glycerol molecule by ester bonds) and the time taken for the phenolphthalein to turn from pink to white compared?
With higher lipase concentrations, there will be more active sites in the solution to be fit in by the substrates, which means more collisions between the active sites and the Substrates and quicker breakdown of lipids in the milk within shorter period of time. At Enzyme concentration of 1% or 2%, reactions can happen at a relatively slower pace, with lipids broken down and phenolphthalein turning from pink to white over a relatively longer time period. At 3%, enzyme activity will speed up with lipids broken down and phenolphthalein turning from pink to white over a relatively shorter time period. At 4% or 5%, enzyme activity will happen significantly faster.
Important note:
During the experiment, sodium carbonate solution and pH indicator, phenolphthalein will be added ahead of lipase enzyme; when the pH is below 8.2, phenolphthalein will turn from pink to colorless. Sodium carbonate solution is added in order to turn the solution alkaline and the indicator pink then back to colorless after lipase is added to catalyst the chemical reaction and speed up the breakdown of lipids into fatty acid in the milk. Fatty acid produced then is going to neutralize the solution with sodium carbonate solution added previously; phenolphthalein will finally turn from pink back to colorless.
Independent Variables: Enzyme concentration- effectiveness of enzyme concentration will be tested at 1%, 2%,3%, 4%, and 5%. Enzyme lipase at the concentrations of 1%, 2%, 3%, 4% will be made by mixing lipase at 5% and distilled water; all these solutions will be contained in different beakers to keep them pure. In order to make 1% lipase, for each 1ml lipase, 4ml distilled water will be added and poured into a beaker; to make 2% lipase, for each 1ml lipase, 3ml distilled water will be added; to make 3% lipase, for each 1ml lipase, 2ml distilled water will be added; in order to make 4% lipase, for each 1ml lipase, 1ml distilled water will be added.

Dependent variable : The time for the phenolphthalein to turn from pink to colorless will be taken using the stopwatch.

Controlled Variables:
Volume of milk used, pH of substrate, Volume of lipase solution, Temperature

Controlled Variables:
Controlled Variables:
why they are controlled
1- Volume of the milk Volume of the milk used for every test will be kept constantly at 5ml; substrate concentration will be kept the same since full-cream milk will be used. Different volumes of milk will allow different amount of substrates to be contained in the milk. Therefore, more substrates contained in the milk will take it more time for the enzyme to break all the fats while